In recent years, there are proposed a control system for controlling household appliances installed in a house from outside the house before the user returns home, with use of a portable information terminal such as a smartphone or a tablet PC, and an application for a portable information terminal constituting the control system.
For instance, Patent Literature 1 discloses the following technique. Specifically, an air conditioner is operated at a time earlier than the timer-set time of the air conditioner designated by the user by a predetermined time period. Meanwhile, when the user transmits an electronic mail instructing to change the timer-set time from a portable information terminal, the timer-set time is changed, and the air conditioner is operated at a time earlier than the timer-set time after the change by a predetermined time period. Further, when the user transmits an electronic mail instructing to operate the air conditioner from the portable information terminal, the air conditioner is operated.
The technique disclosed in Patent Literature 1, however, needs further improvement.